Sharing leads/contacts/accounts with specific people

Sharing leads/contacts/accounts with specific people

I have an agency with 3 departments:
- Account managers
- Production 1
- Production 2

...and we got 100+ clients and growing.

How can i use zoho crm efficiently so we can set access for individual account/contact/lead access to specific people. The records should not be accessable to anyone else (except the CEO/Department head). The people that need access to Client #1 could typically be 1 account manager, 1 from production 1, and 1 from production 2. The people can change at any time.

How can we achieve this at scale? I assumed that I easily would have an option for each record to just select which people would be able to view that individual record, but cant find that option.

This is a possible deal breaker for investing in zoho